Process of making chrysazin.



UNITED STATES Patented July 19, 1904.

PATENT OFFICE.

ROBERT E. SCHMIDT, OF ELBERFELD, AND PAUL TUST, OF VOHVVINKEL,

NEAR ELBERFELD, GERMANY, ASSIGNORS TO FARBENFABRIKEN OF EL- BERFELD 00., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF MAKING CHRYSAZIN.

BPEGIFICATION forming part of Letters Patent N0. 765,637, dated July 19, 1904.

Original application filed December 10, 1903, Serial No. 184,670. Divided and this application filed May 18, 1904. Serial No. 208,617. (No specimens.)

To all whom it may concern.-

Be it known that we, ROBERT E. SCHMIDT, doctor of philosophy, chemist, residing at Elberfeld, Germany, and PAUL TUs'r, chem- 5 ist, residing at Vohwinkel, near Elberfeld,

Germany, (assignors to the FARBENFABRIKEN OF ELBERFELD COMPANY, of New York,) have invented a new and useful Improvement in Processes of Making Chrysazin; and we here- I by declare the following to be a clear and exact description of our invention.

The present application is a divisional application of our application Serial N 0. 184,670, filed December 10, 1903.

In carrying out our process practically we can proceed as follows, the parts being by weight: I

Example 1: In an autoclave provided with a stirrer a mixture of twenty-five parts of the sodium salt of 1.8-anthraquinone disulfonic acid, thirty parts of calcium hydroxid, (Oa[OH]2,) and four hundred parts of Water is heated to from 180 to 190 'centigrade for about fourteen hours while stirring. After 5 cooling the resulting chrysazin is precipitated from the reaction mass by the addition of hydrochloric acid. It is then isolated by filtration.

Example 2.: In an autoclave provided with 3 a stirrer a mixture of ten parts of the potassium salt of 1.8-anthraquinonedisulfonic acid, thirty parts of crystallized barium hydroxid, (Ba[OH]2,) and one hundred and fifty parts of water is heated to from 170 to 180 centigrade for about ten hours while stirring.

After cooling the resulting chrysazin is precipitated from the reaction mass by the addition of hydrochloric acid. It is then isolated by filtration.

4 The process proceeds in an analogous manline earth, .and then separating the resulting 1.8-dioxyanthraquinone from the reaction mass, substantially as hereinbefore described.

2. The new process for producing 1.8-dioxyanthraquinone, which process consists in first heating an aqueous mixture containing 1.8-anthraquinone disulfonic acid and a mixture of alkaline earths, and then separating the resulting 1.8-dioxyanthraquinone from the reaction mass, substantially as hereinbefore described. 7

3. The new process for producing 1.8-dioxyanthraquinone which process consists in first heating a mixture of 1.8-anthraquinone 5 disulfonic acid with barium hydroxid and water to from to centigrade, secondly acidulating the reaction mass with hydrochloric acid, and finally isolating the resulting 1.8-dioxyanthraquinone from the re- 7 action mixture, substantially as hereinbefore described.

In testimony whereof we have signed our names in the presence of two subscribing witnesses.

ROBERT E. SCHMIDT. PAUL TUST. Witnesses:

OTTO KoNIe, J. A. RITTERsHAUs. 

